Ideal camera lens should have the following conditions when imaging:                a. Dots should be imaged as dots.        b. Faces right ahead should be imaged perpendicular to optical axis as the right faces.        c. Object to be shot should be similar to image producing from lens.        d. Colors of image should be presented true.        
Theoretically, neglecting areas outside the optical axis of the imaging face can produce a standard image. However, regular picture taking uses large aperture to have enough light. Focus is not limited to near optical axis area but everywhere on the screen. Thus, due to spherical surface effect of the lens, object point will not be an ideal object point when shooting. Location of focus also differs from different length of optical waves. Image difference from ideal image due to optical limitation is called aberration.
Currently vendors will process many function tests on the camera lens to ensure the camera lens to be sold meet the optical specifications. There are two common camera lens tests in industry: orthogonal projection test and inverse projection.
Please refer to FIG. 1A, wherein the orthogonal projection test is to put a fixed test pattern 100 on the object side of the camera lens to be tested 110. By using camera 120 at the image side to capture the image of the test pattern 100, function of camera lens to be tested 110 can be further determined.
Please also refer to FIG. 1B, wherein the inverse projection test is to produce a mask 140 for the test pattern, irradiate the test pattern by a collimator 130, and project to the projection area 150 by object side of the camera lens to be tested 110. Thus function of the camera lens to be tested can be analyzed by observing the quality of image pattern in the projection area 150.
Currently the camera lens calibration systems and methods comprise:                1. Diffraction single point focus machine, which is an equipment using the wave property of light to determine the coaxiality of the lens assembly by the quality of the diffraction core image. The disadvantage is that the quality of ambient modular transfer function (MTF) cannot be ensured when focusing. In addition, some of the optical system cannot be focused because the diffraction core image is not sensitive to the relative lens movement.        2. Using CMOS module and image processing component to analyze pattern and perform comparison by bar transmission mechanism. The disadvantage is the high expense of the CMOS module, computer and bar transmission module for processing image and auto focus function. In addition, the automatic focusing takes a long time. Moreover, it needs manual operation to adjust camera lens after computer data detection. The disadvantage is that the manual operation will require the operator to see the data showing on the computer screen and to adjust the required relative moving distance of X/Y axis of the camera lens platform. It further requires large labor cost and the focus time is too long.        
The present methods or devices of focus have the problems of long focus time, high labor cost or high reducing cost. Thus, developer of the present invention considers the disadvantages above and designs a camera lens calibration system to improve the disadvantages of the current technique and increase the application in industry.